Related papers: Temperature profiles of young disk-like structures…

Ice is ubiquitous in the interstellar medium. We model the formation of the main constituents of interstellar ices, including H2O, CO2 , CO, and CH3 OH. We strive to understand what physical or chemical parameters influence the final…

A model is presented which calculates the gas temperature and chemistry in the surface layers of flaring circumstellar disks using a code developed for photon-dominated regions. Special attention is given to the influence of dust settling.…

Aims. To understand the roles of infall and protostellar evolution on the envelopes of massive young stellar objects (YSOs). Methods. The chemical evolution of gas and dust is traced, including infall and realistic source evolution. The…

The disks that orbit young stars are the essential conduits and reservoirs of material for star and planet formation. Their structures, meaning the spatial variations of the disk physical conditions, reflect the underlying mechanisms that…

We have analyzed rotational spectral line emission of OCS, CH3OH, HCOOCH3, and H2CS observed toward the low-mass Class 0 protostellar source IRAS 16293-2422 Source A at a sub-arcsecond resolution (~0".6 x 0".5) with ALMA. Significant…

In Paper-I we presented a methodology to recover the spatial variations of properties of the intracluster gas from ASCA X-ray satellite observations of galaxy clusters. We verified the correctness of this procedure by applying it to…

A snow-line is the region of a protoplanetary disk at which a major volatile, such as water or carbon monoxide, reaches its condensation temperature. Snow-lines play a crucial role in disk evolution by promoting the rapid growth of…

Midplane heating induced by disk accretion plays a key role in determining the disk temperature particularly at the inner disk midplane where planets form. However, the efficiency of accretion heating has been not well constrained by…

Circumplanetary disks can be found around forming giant planets, regardless of whether core accretion or gravitational instability built the planet. We carried out state-of-the-art hydrodynamical simulations of the circumplanetary disks for…

It is known that the external irradiation of protoplanetary disks by nearby massive stars can result in mass loss that impacts the disk evolution, however the dynamical impact of external irradiation upon the disk itself has not been…

Planets are supposed to form in circumstellar disks. The gravitational potential of a planet perturbs the disk and leads to characteristic structures, i.e. spiral waves and gaps, in the disk's density profile. We perform a large-scale…

We have investigated molecular distributions in protoplanetary disks, adopting a disk model with a temperature gradient in the vertical direction. The model produces sufficiently high abundances of gaseous CO and HCO+ to account for line…

We present deep images of dust continuum emission at 450, 800, and 850 micron of the dark cloud LDN 1689N which harbors the low-mass young stellar objects (YSOs) IRAS 16293-2422A and B (I16293A and I16293B) and the cold prestellar object…

Turbulence can transport angular momentum in protoplanetary disks and influence the growth and evolution of planets. With spatially and spectrally resolved molecular emission line measurements provided by (sub)millimeter interferometric…

Massive infrared dark clouds (IRDCs) are considered to host the earliest stages of high-mass star formation. In particular, 70 $\mu$m dark IRDCs are the colder and more quiescent clouds. At a scale of about 5000 au using formaldehyde (H2CO)…

Understanding the thermal structure of protoplanetary disks is crucial for modeling planet formation and interpreting disk observations. We present a new two-layer radiative transfer model for computing the thermal structure of axisymmetric…

We analytically derive the expressions for the structure of the inner region of protoplanetary disks based on the results from the recent hydrodynamical simulations. The inner part of a disk can be divided into four regions: dust-free…

JWST/MIRI has sharpened our infrared eyes toward the star formation process. This paper presents the first mid-infrared detection of gaseous SO$_2$ emission in an embedded low-mass protostellar system. MIRI-MRS observations of the low-mass…

Our current understanding of the physical conditions in the inner regions of protoplanetary discs is becoming increasingly challenged by the more detailed observational and theoretical explorations. Calculation of dust temperature is one of…

This paper presents a systematic survey of the deuterated and 13C isotopologues of a variety of oxygen-bearing complex organic molecules on Solar System scales toward the protostar IRAS 16293-2422B. We use the data from an unbiased…